No Arabic abstract
Liquid argon detectors, with mass up to 100 kton, are being actively studied in the context of proton decay searches, neutrino astrophysics and for the next generation of long baseline neutrino oscillation experiments to study the neutrino mass hierarchy and CP violation in the leptonic sector. The proposed Giant Liquid Argon Charge Imaging ExpeRiment (GLACIER) offers a well defined conceptual design for such a detector. In this paper we present the GLACIER design and some of the R&D activities pursued within the GLACIER.
Elegant experiments are being carried out, or are in preparation, to improve the precision with which the solar and atmospheric neutrino-oscillation parameters are known, and to attempt to make a first measurement of the small mixing angle $theta_{13}$. The compelling case for the development of an accelerator-based neutrino source to serve the programme of precision measurements of neutrino oscillations and sensitive searches for leptonic-CP violation that is required to follow these experiments is briefly reviewed. The Neutrino Factory, an intense high-energy neutrino source based on a stored muon beam, is widely believed to yield a precision and sensitivity superior to other proposed second-generation facilities. The alternatives are identified and the case for a critical comparison of the performance of the various options is presented. Highlights of the exciting international R&D programmes which are designed to demonstrate the feasibility of the required techniques are then reviewed. The steps that the international community is taking to produce, by the end of the decade, a full conceptual design for the facility are described. The ambition of the Neutrino Factory community is to demonstrate the feasibility of a cost-effective design such that, should forthcoming measurements show that it is required, the facility could be brought into operation in the second half of the next decade.
Recent results on the particle detector R&D for new accelerators are reviewed. Different approaches for the muon systems, hadronic and electromagnetic calorimeters, particle identification devices, and central trackers are discussed. Main emphasis is made on the detectors for the International Linear Collider and Super B-factory. A detailed description of a novel photodetector, a so called Silicon Photomultiplier, and its applications in scintillator detectors is presented.
The Santa Cruz Institute for Particle Physics (SCIPP) continues to be engaged in research and development towards an ILC detector. The latest efforts at SCIPP are described, including those associated with the LSTFE front-end readout ASIC, the use of charge division to obtain a longitudinal coordinate from silicon strip detectors, and the contribution of strip resistance to readout noise.
Significant progress has been made to develop silicon pixel technologies for use in the vertex and tracker regions of the proposed Compact Linear Collider (CLIC) detector design. The electron-positron collisions generated by this linear accelerator provide a clean, low-radiation environment for the inner detectors. However, physics-driven performance targets, the CLIC beam structure, and occupancies from beam-induced backgrounds place challenging requirements on detector technologies for this region. A pixel pitch down to 25 x 25$mu$m$^{-2}$, material budget $leq$ 0.2-2$%X_0$ per layer, average power dissipation of down to 50mWcm$^{-2}$, position resolution of 3-7$mu$m, and timing resolution as low as 5ns are called for in the vertex and tracking detectors. To this aim, a comprehensive R&D programme is ongoing to design and test silicon pixel detectors to fulfil these specifications, including both monolithic and hybrid devices. These studies involve Allpix$^2$ Monte Carlo and TCAD simulations, advanced 65nm ASIC and sensor design, laboratory testing, and beam tests of individual modules to determine the required performance parameters. The characterisation and simulation modelling of these devices has also lead to the development of a set of tools and software within the CLIC detector and physics (CLICdp) collaboration. This publication will present recent results from the technologies being developed and tested in view of the CLIC vertex and tracking detector requirements, such as various monolithic CMOS sensors, and fine pitch hybrid assemblies with planar sensors.
Two special calorimeters are foreseen for the instrumentation of the very forward region of an ILC or CLIC detector; a luminometer (LumiCal) designed to measure the rate of low angle Bhabha scattering events with a precision better than 10$^{-3}$ at the ILC and 10$^{-2}$ at CLIC, and a low polar-angle calorimeter (BeamCal). The latter will be hit by a large amount of beamstrahlung remnants. The intensity and the spatial shape of these depositions will provide a fast luminosity estimate, as well as determination of beam parameters. The sensors of this calorimeter must be radiation-hard. Both devices will improve the e.m. hermeticity of the detector in the search for new particles. Finely segmented and very compact electromagnetic calorimeters will match these requirements. Due to the high occupancy, fast front-end electronics will be needed. Monte Carlo studies were performed to investigate the impact of beam-beam interactions and physics background processes on the luminosity measurement, and of beamstrahlung on the performance of BeamCal, as well as to optimise the design of both calorimeters. Dedicated sensors, front-end and ADC ASICs have been designed for the ILC and prototypes are available. Prototypes of sensor planes fully assembled with readout electronics have been studied in electron beams.